In synchronous electric machines, the salient poles in the rotor, which carry the excitation winding, can be configured without pole shoes. In this connection, reference may be had to Leitfaden der Elektrotechnik by Moeller-Werr, Vol. III, 3.ed., page 42. With this configuration, there is obtained a pole gap of approximately rectangular shape wherein the excitation windings can be put in place very simply in the radial direction. The excitation winding fills the pole gaps practically completely and is held in place by slot wedges. This, however, means that the removal of the heat generated in the excitation windings by air cooling cannot be effected at least in the region of the pole gaps.
It is an object of the invention to provide an excitation winding arrangement wherein the advantage of simple mounting of the excitation winding in the radial direction in a synchronous electric machine is retained and nevertheless an effective cooling of the excitation winding by air achieved.